Art,
Unquestionably. Vryhof has two test tanks in Holland (one soft, the other hard soil) and per my USA contact who is based out of Houston, they have a significant amount of underwater footage which illustrates anchor behavior in various soil conditions.
Here's a link to their new 172 page anchor manual which I think will be of great interest to the esteemed anchor gurus on this forum:
http://www.vryhof.com/flipbooks/am2015/#
Be safe,
Brian
Brian - I'm impressed with the anchor manual! Thanks - Art